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Comment by Xamayon | Hacker News Reader

At this point, with all the easily producible collisions, the Gov't could just modify some CSAM images to match the hash of various leaked documents/etc they want to track. Then they don't even have to go thru special channels. Just submit the modified image for inclusion normally! (Not quite that simple, as they would still need to find out about the matches, but maybe that's where various NSA intercepts could help...)

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Not quite, a CSAM hash match triggers another match within Apple to avoid false positives and then a human review. It wouldn't be trivial for them to extract matches out of that, and they'd only be able to track files they already know the contents for.

I would think they could more easily just make your phone carrier install a malware update on your phone, rather than jumping through all of these hoops to get them access they already have.

Plenty of data is leaking out of people's phones already as can be seen from, e.g. the Parler hack.

I tried to address the issue with finding out about the match at the end of my comment. I agree it's not exactly practical without other serious work to intercept the alerts, have 'spies' in the apple review process, etc. Much easier ways would exist at that point, but it's somewhat amusing (in a horrifying way) that some bad actor could in theory use modified CSAM as a way to detect the likely presence of non CSAM content using generated collisions.

All of the major tech companies already scan images uploaded to their services so isn't this already theoretically possible now? How is the situation changed by Apple using on-device scanning instead of cloud scanning (considering these images were going to be uploaded into iCloud anyway).

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